The invention relates to a tensioning device for tensioning lines, particularly chains or belts, having a rotatable drive element serving to wind up the tensioning line, at least one ratchet wheel connected integrally in rotation to the latter, and exhibiting directionally oriented notches, and a pivot lever serving to introduce the rotary movement into the drive element, on which a drive pawl cooperating with the ratchet wheel is mounted slidably counter to the action of a spring and which is provided with at least one control cam to transfer a blocking mechanism associated with the ratchet wheel into an inoperative position, whilst the notches of the ratchet wheel are shaped so that they are retained firmly by the detent pawl during movement of the pivot lever in one direction, whereas during the movement of the pivot lever in the opposite direction they are entrained by the latter via the drive pawl.
A tensioning device of the type in question is known from U.S. Pat. No. 4,199,182, wherein the free end of the tensioning lever must be moved away from the tensioning device in order to tension the tensioning line. Such a construction of the tensioning device cannot be satisfactory from the ergonomic standpoint. This applied particularly in cases where the tensioning device is used to lash down loads on vehicle.